US3008042A - Humping rate indication system - Google Patents

Description

NOV. 7, 1961 s PHELPS 3,008,042

HUMPING RATE INDICATION SYSTEM Filed Oct. 1, 1957 2 Sheets-Sheet 1 FIG. I.

s DIRECTIONAL I 5 RETARDEK /ANTENNA l5 CREsT OF HUMP WEIGHING RAII. l8

WEIGHT TRANSMITTER DETECTOR 1 RECEIVER T 24 RETARDER DISCRIMIN- OPERATING MECHANISM 25 FIGZ. RELAY WEIGHING DEVICE CONTROL 23 24 CIRCUITS RETARDER OPERATING MECHANISM E RESTORE PB 2 i 8 IT I+) T 7- S SIGNAL AT CREST INVENTOR.

SMPHELPS HIS ATTORNEY Nov. 7, 1961 s. M. PHELPS 3,008,042

HUMPING RATE INDICATION SYSTEM Filed Oct. 1, 1957 2 Sheets-Sheet 2 30 5 o 2 6m m x Eozw ook J mmkz Sm v6 wEwomEz. N02 50 v6 WEMGEPZ oz .50

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HIS ATTORNEY United States Patent 3,008,042 HUMPING RATE INDICATION SYSTEM Stuart M. Phelps, Rochester, N.Y., assignor to General Railway Signal Company, Rochester, N.Y. Filed Oct. 1, 1957, Ser. No. 687,403 4 Claims. (Cl. 246110) This invention relates to the detection of the frequency at which railroad cars are pushed over the crest of the, hump in a railway classification yard, and more particularly measures the time interval between successive cars at a certain stage in their progression.

In a classification yard, a train of railroad cars is pushed over the crest of a hump, and each car is allowed to roll by gravity down the hump and over a number of route-selecting switches to a particular one of a number of destination tracks. When several consecutive cars are to go to the same destination track, they are usually left coupled together and allowed to roll together to their destination track; such a group of cars heing idenified as a cut, although, a cut obviously could consist of a single car. The cuts are classified as to their particular destination and routed to a particular destination track to complete a train make-up.

The grade of the hump is of sufiicient elevation so as to permit the car with the hardest rolling characteristics to reach the most remote destination in the classification .track and still have a speed great enough to cause eifective coupling. Cars which have easier rolling characteristics, must be decelerated so that they too will reache their destination with suitable coupling speeds. This deceleration is provided in the form of car retarder mechanisms located along the track rails. The car retarders have brake shoe beams which apply controllable braking pressure to the rims of the car wheels. In rolling from the crest of the hump, the cars are switched from thier main track to a plurality of branch tracks and then over various additional switches to their final destination tracks. One or more car retarders are located along the main track and are usually called hump retarders. Addtiional car retarders are included in some of the branch tracks as well so that the speed of each car or cut can be controlled for the particular conditions: relating to the group of tracks it will travel over, and these retarders are usually called group retarders. Other retarders are sometimes added at various points along the classification tracks as the need for increased retardation control may demand.

In the past it has been the practice to have the braking effect of the various retarders controlled by an operator who observes the speed of each car or cut and then takes into account the cars weight, its rolling characteristics, destination, and other factors to determine how much retardation should be applied. Many classification yards in use today still retain such manual control, however, various devices have been provided to enable the operator to more accurately make his determination as to the proper braking pressure to be applied. Recently, the amount of trafiic has required the railroads to modernize their classification yard systems so as to provide completely automatic control of all phases of car movements through the classification yard systems. Such automatic control has as a few of its essential elements such devices as automatic Weight detecting apparatus, speed measuring devices, route selecting controls and numerous other aids. In order for the more recently developed automatic controls to function properly, the spacing between the cars or cut of cars being pushed over the crest of the hump must be at an interval of time which will provide enough time for such automatic controls to complete their cycle of operation. On the other hand, the efiiciency of an automatic classification yard system is generally rated 3,008,042 Patented Nov. 7, 1961 as to the speed at which cars may be pushed over the crest of the hump and routed to their particular destination tracks.

The present invention provides a means for determining the interval of time between successive cars or cut of cars, to enable an interval to be selected so as to result in the maximum humping speed yet providing ample time for the automatic retarder and switching controls to complete their cycle of operation.

Although the present invention, as will be apparent from the description that follows, has been shown in a classification yard in which an automatic retarder control system has been used, obviously, the cut interval detection means described hereinafter can be utilized in a classification yard in which manual control is still used. In this connection, as stated before, the weight of a car or cut of cars is determined by a weight detector device regardless of whether the remainder of the system is automatically controlled or manually controlled. With only slight modification the present invention can be actuated by any repetitious event that occurs upon the arrival of a car or cut of cars at a certain track location and is therefore adaptable to manually control classification yards and not limited to yards having automatic retarder control systems exclusively.

Hence, one object of the present invention is to provide a cut interval frequency detecting means wherein the humping speed may be controlled in cooperation with the automatic control system governing car movements throughout the classification yard but such humping speed will be the maximum speed allowable under all conditions.

Another object of the present invention is to provide a means at the crest of the hump wherein the operator or engineer in charge of regulating the humping speed will be notified when such speed exceeds the maximum at which the automatic control system can be eflfective.

Other objects, purposes, and characteristic features of this invention will be in part obvious from the accompanying drawings, and in part pointed out as the description of the invention progresses.

In describing the invention in detail, reference will be made to the accompanying drawings in which like reference characters designate corresponding parts in the separate views, and in which:

FIG. 1 is a block diagram of the general organization of a system in which the present invention may be embodied;

FIG. 2 illustrates a typical circuit for the control of a retarder along with one embodiment of the present invention; and

FIG. 3 constitutes a sequence chart graphically illustrating the mode of operation of the detector system upon passage of cars through a car retarder having an organization as illustrated in FIGS. 1 and 2.

To simplify the illustration and facilitate in the explanation of this invention, various parts and circuits which constitute the embodiment of this invention as shown diagrammatically and certain conventional illustrations are used. The drawings have been made to make it easy to understand the principles and manner of operation rather than to illustrate the specific construction and arrangement of parts that would be used in practice. The various relays and their contacts are shown in a conventional manner and symbols are used to indicate connections to the terminals of batteries or other sources of electric current instead of showing all the wiring connections to make these terminals. The terminals and indicate connections to the opposite terminals of a source of voltage.

As stated before, FIG. 2 illustrates a typical circuit for the control of a retarder along with one embodiment of the present invention. More particularly, FIG. 2 illustrates a portion of a track layout in a completely automatic car classification yard in which the general overall system controls the retarders automatically so that each car or cut of cars leaves a retarder at a speed calculated so as to permit the reaching of the destination track at the desired coupling speed. In the arrangement shown, computing means has been used to determine such variable factors such as vehicle weight, condition of track, net rollability, etc. Further, speed measuring means has also been employed. These automatic devices have generally replaced the educated guess made by the experienced manual operation in the less modern yards. In almost all yards, however, there are detector track relays to indicate to the operator or fix in a computing device the presence of the cut. Hence this cut interval detection system has been made to operate in cooperation with such detector apparatus. More particularly, circuit means energized in accordance with the actuation of the weighing apparatus, also initially energizes the cut interval detection system.

FIG. 1 illustrates the crest over which a train of cars is pushed up the hump and allowed to roll singly or in cuts over the various switches and branching tracks to their final destination tracks. A signal has been placed at this crest for indicating to the operator that the maximum humping speed has been exceeded, all in accordance with the invention described hereinafter. It should be noted, however, that any type of warning apparatus such as an alarm or such could be used in lieu of the signal shown. A retarder is located ahead of the first switch. Additional retardation is provided by retarders located along the branch tracks. Although the track gradient has not been shown, it is assumed that the usual track gradient will be employed so as to allow the cars to roll by gravity from the hump to their intended destination tracks. Near the leaving end of each retarder is shown a directional antenna or other high frequency transmitting means for at times transmitting a signal to a car or cut of cars, which signal is reflected from such car or cut of cars and picked up by appropriate receiving apparatus for the purpose of determining the speed of the car which is computed by appropriate speed measuring apparatus all in a manner known to those skilled in the art. My purpose in illustrating such additional apparatus is merely to indicate that the present invention can be adapted to the most completely automatic car retarder control system and it is understood that the brake pressure applied to these freely rolling vehicles may be applied manually in accordance with the experienced judgment of a hump operator. One example of a completely automatic car retarder control system of this kind is shown and fully described in the pending application of Hugh C. Kendall et al., U.S. Ser. No. 513,364, filed June 6, 1955, now U.S. Patent No. 2,868,534 granted Jan. 13, 1959.

Weighing means is provided just ahead of any retarder on the main tracks and also just ahead of any retarder located along the branch tracks so that the weight of each car or the weight of the heaviest car in a particular cut can be determined. The weighing means may comprise a floating weighing rail 15, as shown, which has associated therewith a weight detector mechanism 16. For purposes of simplicity, the weighing rail, weight detector, and the retarder operating mechanism have been shown by block diagram, however, FIG. 2 schematically illustrates some of the weight storage relays of which the weight detector is comprised and shows the adaptation of the present invention in combination therewith. The weighing rail 15 selectively actuates contacts of the weight detector 16 in accordance with the extent of its deflection. Weighing means of this kind is shown and fully described in the pending application of S. M. Phelps, U.S. Ser. No, 386,095, filed October 14, 1953. Other types of weighing means may also be provided such as an electronic means employing a strain gauge.

Also shown by block diagram are the transmitter-receiver, the discriminator, and the relay control circuits. Although these elements are fully shown and described in the above referred to application of Hugh C. Kendall et al., U.S. Ser. No. 513,364, filed June 6, 1955, it is felt necessary to briefly describe the system for explanatory purposes. The transmitter-receiver 18 supplies a steady, high frequency signal to a directional antenna, and receives from this antenna the signal reflected from each approaching car. This transmitter-receiver 18 has included therein a mixer which mixes the outgoing and incoming signals to provide a difference or beat frequency signal proportional to the car speed. This beat frequency signal is applied to a discriminator 24 which governs the relay control circuits 25 in accordance with the car speed. The transmitter-receiver 18, the directional antenna, and the discriminator may be of any form adaptable for this purpose.

FIG. 2 illustrates a plurality of speed relays S1 and A1 and weight storage relays 1H, 1M and IL all actuated in accordance with the detection of a vehicle entering upon the weighing rail.

Since relay IL is so sensitive that it always picks up when a vehicle enters on the weighing rail 15, the check relay lCK has been made responsive to the energization of the weight storage relay 1L. Thus, when relay IL is energized upon the detection of a vehicle entering on the weighing rail 15, an energizing circuit is completed for the relay ICK from through front contact 23 of relay 1L, through the windings of relay ICK, selections within discriminator 24, to

The check relay ICK is operated by a check relay control circuit in the discriminator 24 in accordance with the amplitude of the beat frequency signal rather than its frequency and relay lCK is operated to be picked up from the time that a car enters upon the weighing rail until the car exits from the retarder. This particular beat frequency signal is obtained from the output of a cathode follower tube fully shown and described in the automatic car retarder control system disclosed in the above referred to application of Hugh C. Kendall et a1. It should be noted also from the disclosure therein that the speed relay S1 and the anticipation relay A 1 likewise may be picked up upon the actuation of the weight detector relays 1H, 1M and IL depending upon their speed settings, but they have inherent release characteristics which cause them to release at different values of car speed for purposes not involved in this invention.

Regardless of the system in which the present invention is used, it is imperative only that the check relay 1CK be actuated by some detecting means which is stationary in the system so as to detect a car or cut of cars at the same point along the track each time. For simplicity, the weighing rail 15 has been selected for purposes of this description to actuate the check relay ICK. Hence when the weighing device is deflected the check relay 10K is energized once by each cut of cars. This relay could be merely a track relay connected across the rails at the crest of the hump or a weight or check relay on a retarder system as shown.

Relay lCKP is a slow pick-up repeater relay of the check relay =1CK and has its front contact 5 so arranged with back contact 4 of relay 1CK so that the normally energized relay C is deenergized between the time that the check relay 1CK is picked-up and the slow acting check repeater relay ICKP is picked-up. With relay C deenergized, the relay D becomes energized. Relay C has been made slow to pick-up while relay D has a slow release characteristic. Since the energization of relay D is dependent upon the deenergization of relay C, a time interval is established between the pick-up and release times of the respective relays.

Relay E is also normally energized and will remain is as long as the time interval between the pickup and release values for relays C and D, respectively, is not exceeded. If, however, the humping interval is too close and the check relay ICK is actuated in accordance with the presence of a car or cut of cars at the weighing rail before said time interval has elapsed, relay B will become deenergized. Since relay E is connected to its energizing source through its own front contact 8 there is no way for relay E to be reenergized except by means of the restoration push button PB. Further, with relay E deenergized, a signal circuit is completed from through back contact '9 of relay E to the signal S, thus lighting said signal lamp which is located at the crest of the classification yard.

More particularly, when the check relay lCK is energized by the presence of a train upon the weighing rail 15 as detected by the weight storage relay 1L, it picks up its front contact 11 completing an energizing circuit for the check repeater relay 1CKP from (+),through front contact 11 of the check relay 1CK, through the winding of relay 1CKP, to The slow-to-pick-up relay C is normally energized through a circuit from through back contact 4 of the check relay lCK, through the winding of relay C, to however, when relay lCK is energized, as explained above, back contact 4 of relay 1CK is opened thus interrupting the energizing circuit for relay C. A second energizing circuit is available for the relay C from through front contact 5 of the repeater relay 1CKP, through the winding of relay C, to Since, however, the check repeater relay 1CKP has been made slow to pick up, this energizing circuit for relay C will not be completed until front contact 5 of relay 1CKP has been closed. This occurs only after a short lapse of time during which lapse of time relay C become deenergized. With relay C deenergized, back contact 6 of relay C is closed to complete an energizing circuit for the relay D from through back contact 6 of relay C, through the winding of relay D, to With relay D momentarily energized because of the momentary deenergization of relay C, back contact 7 of relay D is opened thus interrupting one of the energizing circuits for relay E. Because the time interval for the picking up of the repeater relay 1CKP is of relatively short duration (see FIG. 3), and further, because relay D has not yet picked up its back contact 7, relay E is continuously energized through one of three energizing circuits. The first of these energizing circuits for relay E is from through back contact 4 of check relay lCK, rectifier 3, line wire 2, front contact 8 of relay E, and the winding of relay E, to This circuit maintains the relay E energized when the check relay 1CK is in its deenergized position. A second energizing circuit for relay E extends from through front contact 5 of relay 1CKP, rectifier 3, line wire 2, front contact 8 of relay E, and the winding of relay E, to Once the check repeater relay 1CKP is picked-up this circuit maintains relay E in its energized position. A third energizing circuit for relay E extends from through back contact 7 of relay D, front contact 8 of relay E, and the Winding of relay E to This third energizing circuit maintains the relay E in its energized position during the interval of time that it takes the repeater relay 1CKP to pick-up after the check relay 1CK has been energized by the presence of a car or cut of cars upon the weighing rail.

As stated before, the time interval used to measure the interval between successive cars or cuts of cars is determined by the preselected pick-up and release times of the respective relays C and D. It is apparent, therefore, that if successive cuts follow too closely that the check relay ICK will be energized during this aforementioned time interval and will cause the relay C to drop away within the release time of relay D as can best be seen from the illustrative sequence chart shown in FIG. 3 of the drawings. When such event occurs,

relay D is maintained energized and the preselected time interval is exceeded. With relay D picked-up for a time longer than its normal preselected release time, the third energizing circuit, as described above, will not be closed at back contact 7 of relay D and will not maintain relay E in its energized condition. Since, at the same time, neither the first nor second energizing circuits are closed, relay B will become deenergized opening its front contact 8. Because relay E is connected to its energized circuits through its own front contact 8, it is impossible for any of the three above referred to energizing circuits to again actuate the relay E until front contact 8 is again closed. Hence, a restoration push button PB has been placed in the circuit so that the relay E may be reenergized through a circuit from through back contact 17 of the push button PB, through the winding of relay E to It is understood that although manual restoration means has been indicated herein for the purposes of simplifying the explanation, obviously, automatic restoration means of the type well known in the art may be employed in lieu thereof. Further, when relay E becomes deenergized, back cont-act 9 of relay E is closed to complete an energizing circuit for the signal S which has been shown to be located at the crest of the classification yard, such circuit extending from through back contact 9 of relay E, signal lamp S to As will be seen in FIG. 2 of the drawing, capacitor 33 has been connected across the relay D to provide a better time uniformity in the operation of the relay D. Connected in multiple with the capacitor 33 is a diode 31 connected in series with a resistor 32 for the purpose of maintaining a uniform condenser voltage for all battery voltage. The break-down voltage of this diode may be used to control the maximum voltage to which the capacitor 33 may be charged. When the break-down voltage of the diode 31 has been exceeded, however, it then operates with very low resistance and when subsequently connected in series with the resistor 32, under such condition, actually draws a very minute amount of current through the system. As has been shown, a potentiometer R2 has also "been added in multiple with relay D, the capacitor 33, and the diode arrangement for the purpose of allowing an adjustment of the preselected time interval to be made. Obviously the circuit embodying the present invention described hereinbefore may be operated without such additional elements such as the con denser 33, the diode 31, resistor 32 and potentiometer R2, but, with a poor time uniformity. The method of obtaining a more accurate measurement of time as shown in this auxiliary circuit arrangement is, of course, shown only for the purposes of facilitating in the explanation of the invention and it is understood that other means may be used to accomplish the same purpose such as substituting a motor operated or thermal relay structure for the relay D. A rectifier 3 has been placed in the line wire 2 for the purpose of using only a one wire circuit and, of course, could be eliminated by the addition of another Wire which would result in two independent circuits. Further, if a multiple speed system is desired, additional time relays or the provision of a selector switch to select various of a plurality of potentiometers on the relay D could be used.

Diode 31 is a silicon diode utilized as a voltage regulator by operating such diode 31 in the saturation region of its inverse characteristic. That is, this diode has a particular voltage break-down value, known in the art as Zener voltage which is the voltage associated with that portion of the usual voltage-versus-current characteristic of a semi-conductor device wherein the voltage remains substantially constant over a considerable range of current values. This type of diode and its operating characteristics are fully described in publication No. AN 1352-A issued January, 1957 by the Transitron Electronic Corp.

It has been a well known practice in the past to connect a condenser in multiple with a relay winding to give the relay slow pick-up and slow release characteristics. The uniformity of the relay operation, however, is largely dependent upon the amount of charge which has been built up on the condenser. Also, it is old in the art to connect a rectifier in multiple with a relay to give the relay a slow release characteristic, however, here again, the uniformity of the relay operation is dependent ultimately on the magnitude of the charging current.

The present invention describes a combination of a Zener type diode 31 and a capacitor 33 both connected in multiple with a relay D and with one another, whereby the relay is made slow to release. The importance of such combination lies in the individual characteristics of each element and their effect on the circuit organization during operation. If, for example, the battery voltage at the source of supply is 24 volts, and the condenser 33 has a charging capacity of 20 volts, and further, the break-down voltage of the Zener diode 31 has been selected to be 20 volts, the presence of the Zener diode 31 will always permit the condenser to charge to a maximum of 20 volts above which voltage the Zener diode breaks down, and by its inherent characteristics, becomes a very low resistance thereby discharging any voltage above 20 volts through its inverse characteristic. Hence, when current flows through the inverse characteristic of the diode 31, which in effect shunts the condenser, the IR drop across the resistance 34 keeps the condenser voltage at 20 volts. A second resistor 32 has been placed in series with the diode 31 to prevent damage to the diode after its predetermined break-down voltage value has been exceeded. It should be noted, however, that although the diode breaks down above 20 volts, it is nevertheless efiective for all voltage values up to 20 volts, even after the diode begins to permit a discharge through its inverse characteristic. As is apparent, such combination will assure a uniform condenser voltage for all battery voltages and will result in a system having a uniform release characteristic regardless of the variation in voltage. This combination is adaptable to any relay and will thus permit the use of a type of relay which can be operated hundreds of times daily without breaking down mechanically whereas in the past, the usual motor operated time relay or thermal relay has been found inadequate.

Having thus described one specific embodiment of the present invention, it is desired to be understood that the present invention is not limited to the specific form shown and that various modifications and adaptations can be made to meet the requirements of practice without departing in any manner from the spirit or scope of this invention.

What I claim is:

1. A hump rate indication system for railway classification yards comprising car presence registering means for registering the presence of a car at a particular point along a stretch of railway track, timing means initiated by the actuation of said presence registering means by a car for timing a predetermined time interval, and indication means controlled by said timing means and the car presence registering means for indicating when the car presence registering means is actuated to register the presence of a second car at said particular point before the end of said time interval.

2. A hump rate indication system according to claim 1 wherein the indicating means includes a stick relay and an indicator controlled by the stick relay and means for energizing said stick relay including a stick circuit controlled jointly by said timing means and said car presence registering means.

3. A hump rate indication system according to claim 2 wherein the indicator is a light signal.

4. A hump rate indication system according to claim 2 wherein a pick up circuit is provided for the stick relay including a push button for actuation of the stick relay to its energized position.

References Cited in the file of this patent UNITED STATES PATENTS 2,577,137 Low Dec. 4, 1951 2,583,328 Dimond Jan. 22, 1952 2,623,163 Bone Dec. 23, 1952 2,735,966 Dodd Feb. 21, 1956 2,763,775 Tsiang Sept. 18, 1956 2,769,131 Immel Oct. 30, 1956

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